Improves gtest's failure messages. In particulars, char pointers and

char arrays are not escapped properly.

src/gtest-printers.cc

@@ -183,9 +183,9 @@ static CharFormat PrintAsCharLiteralTo(Char c, ostream* os) {
   return kSpecialEscape;
 }
 
-// Prints a char c as if it's part of a string literal, escaping it when
+// Prints a wchar_t c as if it's part of a string literal, escaping it when
 // necessary; returns how c was formatted.
-static CharFormat PrintAsWideStringLiteralTo(wchar_t c, ostream* os) {
+static CharFormat PrintAsStringLiteralTo(wchar_t c, ostream* os) {
   switch (c) {
     case L'\'':
       *os << "'";
@@ -200,8 +200,9 @@ static CharFormat PrintAsWideStringLiteralTo(wchar_t c, ostream* os) {
 
 // Prints a char c as if it's part of a string literal, escaping it when
 // necessary; returns how c was formatted.
-static CharFormat PrintAsNarrowStringLiteralTo(char c, ostream* os) {
-  return PrintAsWideStringLiteralTo(static_cast<unsigned char>(c), os);
+static CharFormat PrintAsStringLiteralTo(char c, ostream* os) {
+  return PrintAsStringLiteralTo(
+      static_cast<wchar_t>(static_cast<unsigned char>(c)), os);
 }
 
 // Prints a wide or narrow character c and its code.  '\0' is printed
@@ -247,48 +248,63 @@ void PrintTo(wchar_t wc, ostream* os) {
   PrintCharAndCodeTo<wchar_t>(wc, os);
 }
 
-// Prints the given array of characters to the ostream.
-// The array starts at *begin, the length is len, it may include '\0' characters
-// and may not be null-terminated.
-static void PrintCharsAsStringTo(const char* begin, size_t len, ostream* os) {
-  *os << "\"";
+// Prints the given array of characters to the ostream.  CharType must be either
+// char or wchar_t.
+// The array starts at begin, the length is len, it may include '\0' characters
+// and may not be NUL-terminated.
+template <typename CharType>
+static void PrintCharsAsStringTo(
+    const CharType* begin, size_t len, ostream* os) {
+  const char* const kQuoteBegin = sizeof(CharType) == 1 ? "\"" : "L\"";
+  *os << kQuoteBegin;
   bool is_previous_hex = false;
   for (size_t index = 0; index < len; ++index) {
-    const char cur = begin[index];
+    const CharType cur = begin[index];
     if (is_previous_hex && IsXDigit(cur)) {
       // Previous character is of '\x..' form and this character can be
       // interpreted as another hexadecimal digit in its number. Break string to
       // disambiguate.
-      *os << "\" \"";
+      *os << "\" " << kQuoteBegin;
     }
-    is_previous_hex = PrintAsNarrowStringLiteralTo(cur, os) == kHexEscape;
+    is_previous_hex = PrintAsStringLiteralTo(cur, os) == kHexEscape;
   }
   *os << "\"";
 }
 
+// Prints a (const) char/wchar_t array of 'len' elements, starting at address
+// 'begin'.  CharType must be either char or wchar_t.
+template <typename CharType>
+static void UniversalPrintCharArray(
+    const CharType* begin, size_t len, ostream* os) {
+  // The code
+  //   const char kFoo[] = "foo";
+  // generates an array of 4, not 3, elements, with the last one being '\0'.
+  //
+  // Therefore when printing a char array, we don't print the last element if
+  // it's '\0', such that the output matches the string literal as it's
+  // written in the source code.
+  if (len > 0 && begin[len - 1] == '\0') {
+    PrintCharsAsStringTo(begin, len - 1, os);
+    return;
+  }
+
+  // If, however, the last element in the array is not '\0', e.g.
+  //    const char kFoo[] = { 'f', 'o', 'o' };
+  // we must print the entire array.  We also print a message to indicate
+  // that the array is not NUL-terminated.
+  PrintCharsAsStringTo(begin, len, os);
+  *os << " (no terminating NUL)";
+}
+
 // Prints a (const) char array of 'len' elements, starting at address 'begin'.
 void UniversalPrintArray(const char* begin, size_t len, ostream* os) {
-  PrintCharsAsStringTo(begin, len, os);
+  UniversalPrintCharArray(begin, len, os);
 }
 
-// Prints the given array of wide characters to the ostream.
-// The array starts at *begin, the length is len, it may include L'\0'
-// characters and may not be null-terminated.
-static void PrintWideCharsAsStringTo(const wchar_t* begin, size_t len,
-                                     ostream* os) {
-  *os << "L\"";
-  bool is_previous_hex = false;
-  for (size_t index = 0; index < len; ++index) {
-    const wchar_t cur = begin[index];
-    if (is_previous_hex && isascii(cur) && IsXDigit(static_cast<char>(cur))) {
-      // Previous character is of '\x..' form and this character can be
-      // interpreted as another hexadecimal digit in its number. Break string to
-      // disambiguate.
-      *os << "\" L\"";
-    }
-    is_previous_hex = PrintAsWideStringLiteralTo(cur, os) == kHexEscape;
-  }
-  *os << "\"";
+// Prints a (const) wchar_t array of 'len' elements, starting at address
+// 'begin'.
+void UniversalPrintArray(const wchar_t* begin, size_t len, ostream* os) {
+  UniversalPrintCharArray(begin, len, os);
 }
 
 // Prints the given C string to the ostream.
@@ -314,7 +330,7 @@ void PrintTo(const wchar_t* s, ostream* os) {
     *os << "NULL";
   } else {
     *os << ImplicitCast_<const void*>(s) << " pointing to ";
-    PrintWideCharsAsStringTo(s, wcslen(s), os);
+    PrintCharsAsStringTo(s, wcslen(s), os);
   }
 }
 #endif  // wchar_t is native
@@ -333,13 +349,13 @@ void PrintStringTo(const ::std::string& s, ostream* os) {
 // Prints a ::wstring object.
 #if GTEST_HAS_GLOBAL_WSTRING
 void PrintWideStringTo(const ::wstring& s, ostream* os) {
-  PrintWideCharsAsStringTo(s.data(), s.size(), os);
+  PrintCharsAsStringTo(s.data(), s.size(), os);
 }
 #endif  // GTEST_HAS_GLOBAL_WSTRING
 
 #if GTEST_HAS_STD_WSTRING
 void PrintWideStringTo(const ::std::wstring& s, ostream* os) {
-  PrintWideCharsAsStringTo(s.data(), s.size(), os);
+  PrintCharsAsStringTo(s.data(), s.size(), os);
 }
 #endif  // GTEST_HAS_STD_WSTRING